<ul cdkListbox class="demo-listbox"
    [multiple]="multiSelectable"
    [useActiveDescendant]="activeDescendant"
    [formControl]="formControl" ngDefaultControl>
  <li cdkOption>Apple</li>
  <li cdkOption>Orange</li>
  <li cdkOption>Grapefruit</li>
  <li cdkOption>Peach</li>
</ul>

<button (click)="disableForm()">Disable Form</button>
<br>
<button (click)="toggleMultiple()">Toggle Multiple</button>
<br>
<button (click)="toggleActiveDescendant()">Toggle Active Descendant</button>
